/*
 * The MIT License
 *
 * Copyright (c) 2013-2016 reark project contributors
 *
 * https://github.com/reark/reark/graphs/contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package io.reark.reark.utils;

import android.support.annotation.NonNull;

import java.util.ArrayList;
import java.util.List;

import io.reactivex.Observable;

import static io.reark.reark.utils.Preconditions.checkNotNull;
import static io.reark.reark.utils.Preconditions.get;

public final class RxUtils {

    private RxUtils() {
        throw new AssertionError();
    }

    @NonNull
    public static <T> Observable<List<T>> toObservableList(@NonNull final List<Observable<T>> observables) {
        return Observable.combineLatest(get(observables), RxUtils::toList);
    }

    @NonNull
    @SuppressWarnings("unchecked")
    static <T> List<T> toList(@NonNull final Object... args) {
        checkNotNull(args);

        final List<T> list = new ArrayList<>(args.length);
        for (Object item : args) {
            list.add((T) item);
        }
        return list;
    }
}
